LED lamp having passive heat dissipating element and two heat dissipating channel

ABSTRACT

An LED (light emitting diode) lamp comprising: a lamp shell; a passive heat dissipating element having a heat sink connected to the lamp shell, wherein the heat sink comprises fins and a base; a power source disposed in the lamp shell; a light emitting element connected to the base of the heat sink of the passive heat dissipating element and comprising LED chips electrically connected to the power source; a first channel defined in a chamber of the lamp shell for dissipating heat generated from the power source while the LED lamp is working; and a second channel defined in the heat sink and between the fins and the base for dissipating the heat of the heat sink, which is generated from the LED chips and transferred to the heat sink; wherein the first channel comprises a first end on the light emitting element to allow air flowing from outside of the LED lamp into the chamber, and a second end on the upper portion of the lamp shell to allow air flowing from inside of the chamber out to the LED lamp; wherein the second channel comprises a third end on the light emitting element to allow air flowing from outside of the LED lamp into the second channel, and flowing out from spaces between every adjacent two of the fins; wherein the light emitting element further comprises an aperture communicating simultaneously with both the first channel and the second channel by connecting with the first end of the first channel and the third end of the second channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 16/267,747 filed on 2019 Feb. 5, which claims priority to thefollowing Chinese Patent Applications No. CN 201810130085.3 filed on2018 Feb. 8, CN 201810479044.5 filed on 2018 May 18, CN 201810523952.Xfiled on 2018 May 28, CN 201810573322.3 filed on 2018 Jun. 6, CN201810634571.9 filed on 2018 Jun. 20, CN 201810763800.7 field on 2018Jul. 12, CN 201810763089.5 filed on 2018 Jul. 12, CN 201810972904.9filed on 2018 Aug. 24, CN 201811172470.0 filed on 2018 Oct. 9, CN201811295618.X filed on 2018 Nov. 1, CN 201811299410.5 filed on 2018Nov. 2, CN 201811347198.5 filed on 2018 Nov. 13, CN 201811378174.6 filedon 2018 Nov. 19, and CN 201811466198.7 filed on 2018 Dec. 3, thedisclosures of which are incorporated herein in their entirety byreference.

FIELD OF THE INVENTION

The invention relates to lighting, particularly to LED lamps withpassive heat dissipating element and two heat dissipating channel.

BACKGROUND OF THE INVENTION

Because LED lamps possess advantages of energy saving, high efficiency,environmental protection and long life, they have been widely adopted inthe lighting field. LED lamps as an energy-saving green light source, aproblem of heat dissipation of high-power LED lamps becomes more andmore important. Overheating will result in attenuation of lightingefficiency. If waste heat from working high-power LED lamps cannot beeffectively dissipated, then life of LED lamps will be directly fatallyaffected. As a result, in recent years, solution of the problem of heatdissipation of high-power LED lamps is an important issue for theindustry.

OBJECT AND SUMMARY OF THE INVENTION

An object of the invention is to provide an LED lamp which is capable ofsolving the abovementioned problems.

The LED lamp provided by the invention includes an LED (light emittingdiode) lamp comprising: a lamp shell; a passive heat dissipating elementhaving a heat sink connected to the lamp shell, wherein the heat sinkcomprises fins and a base; a power source disposed in the lamp shell; alight emitting element connected to the base of the heat sink of thepassive heat dissipating element and comprising LED chips electricallyconnected to the power source; a first channel defined in a chamber ofthe lamp shell for dissipating heat generated from the power sourcewhile the LED lamp is working; and a second channel defined in the heatsink and between the fins and the base for dissipating the heat of theheat sink, which is generated from the LED chips and transferred to theheat sink; wherein the first channel comprises a first end on the lightemitting element to allow air flowing from outside of the LED lamp intothe chamber, and a second end on the upper portion of the lamp shell toallow air flowing from inside of the chamber out to the LED lamp;wherein the second channel comprises a third end on the light emittingelement to allow air flowing from outside of the LED lamp into thesecond channel, and flowing out from spaces between every adjacent twoof the fins; wherein the light emitting element further comprises anaperture communicating simultaneously with both the first channel andthe second channel by connecting with the first end of the first channeland the third end of the second channel.

Preferably, the aperture is located in a central region of the lightemitting element, and the aperture forms an air intake of both the firstchannel and the second channel.

Preferably, the light emitting element comprises a first surface and asecond surface which is opposite to the first surface, the LED chips aremounted on the first surface and surrounding the aperture, and thesecond surface is in contact with the base of the heat sink, such thatheat generated from the LED chips is able to be transferred to the finsthrough the base while the LED lamp is working.

Preferably, the heat sink comprises first fins and second fins, bottomsof both the first fins and the second fins in an axis of the LED lampconnect to the base, the first fins interlace with the second fins atregular intervals, and one of the second fins includes a third portionand two fourth portions, the two fourth portions are symmetrical aboutthe third portion.

Preferably, the lamp shell including a lamp head, a lamp neck and asleeve, the lamp head connects to the lamp neck which connects to thesleeve.

Preferably, the power source having a first portion and a secondportion, the first portion of the power source is disposed in both thelamp neck and the lamp head of the lamp shell, and the second portion ofthe power source is disposed in the heat sink of the passive heatdissipating element.

Preferably, further comprising a lamp cover with a light output surfaceand an end surface, wherein the end surface is formed with a vent to letair flowing from outside of the LED lamp into both the first channel andthe second channel through the vent.

Preferably, the first end is projected onto the end surface in an axisof the LED lamp to occupy an area on the end surface, which is definedas a first portion, another area on the end surface is defined as asecond portion, and the vent in the first portion is greater than thevent in the second portion in area.

Preferably, a ratio of power of the LED lamp to heat dissipating area ofthe heat sink is 1:20˜30.

Preferably, the ratio of power of the LED lamp to heat dissipating areaof the heat sink is 1:22˜26.

Preferably, the ratio of power of the LED lamp to heat dissipating areaof the heat sink is 1:25.

Preferably, a volume of the heat sink accounts for 20%˜60% of an overallvolume of the LED lamp.

Preferably, the volume of the heat sink accounts for 25%˜50% of anoverall volume of the LED lamp.

Preferably, overall weight of the LED lamp is less than 1.7 Kg, When theLED lamp is provided with power of 200 W, the LED chips are lit up andemit luminous flux of at least 25000 lumens.

Preferably, further comprising an inner reflecting surface disposedinside the light output surface of the lamp cover and an outerreflecting surface disposed in the outer circle of the array of the LEDchips, wherein the inner reflecting surface is configured to reflectpart of light emitted from the inmost of the array of LED chips, theouter reflecting surface is configured to reflect part of light emittedfrom the outermost of the array of LED chips.

Preferably, total luminous flux of the light reflected by both the innerreflecting surface and the outer reflecting surface and emitted throughthe light output surface is at least 1500 Im.

Preferably, the sleeve of the lamp shell is located in the heat sink,the lamp neck projects from the heat sink, height of the lamp neck is atleast 80% of height of the heat sink.

Preferably, each of the first fins is divided into two portions in aradial direction of the LED lamp, the two portions are divided with agap portion, the third portion is connected to the fourth portionthrough a transition portion, the transition portion has a buffersection and a guide section, a direction of any tangent of the guidesection is separate from the gap portion.

Preferably, in the projected area of the LED lamp, there is a lightconcentrating area within the projected area, and luminous flux of thelight projected by the LED lamp onto the light concentrated areaaccounts for 35%˜50% of the total luminous flux.

Preferably, at least partially of fin has a protrusion projecting from asurface of the fin, the protrusions extend along an axis of the LED lampand are in contact with the base.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed descriptions, given by way of example, and notintended to limit the present invention solely thereto, will be best beunderstood in conjunction with the accompanying figures:

FIG. 1 is a structural schematic view of an embodiment of the LED lampthe invention;

FIG. 2 is a schematic cross-sectional view of the LED lamp of FIG. 1;

FIG. 3 is an exploded view of the LED lamp of FIG. 1;

FIG. 4 is a schematic cross-sectional view of the LED lamp of FIG. 1,which shows the first heat dissipating channel and the second heatdissipating channel;

FIG. 5 is a perspective view of the LED lamp of FIG. 1;

FIG. 6 is a structural schematic view of FIG. 5 without the light outputsurface;

FIG. 7 is a schematic view of light projection of the LED lamp of FIG.1;

FIG. 8 is a light pattern of FIG. 7;

FIG. 9 is a schematic view of an end surface of the lamp cover of anembodiment;

FIGS. 10A˜10I are schematic views of some embodiments of the lamp cover;

FIG. 11 is a perspective view of an LED lamp, according to anotherembodiment of the present invention;

FIG. 12 is a cross-sectional view of the LED lamp of FIG. 11;

FIG. 13 is a top view of the heat sink of the LED lamp of FIG. 11;

FIG. 14 is an enlarged view of portion E in FIG. 13;

FIG. 15 is a schematic view showing a vortex formed by air near thesecond fins according to another embodiment of the present invention;

FIG. 16 is a partially schematic view of the heat sink of anotherembodiment;

FIG. 17 is a main view of an LED lamp of another embodiment;

FIG. 18 is a bottom view of the LED lamp of FIG. 1 without the lampcover;

FIGS. 19A˜19C are perspective views of the power source, according tosome embodiments of the present invention;

FIG. 20 is a block diagram of the power module of an embodiment of theinvention;

FIG. 21 is a circuit diagram of an EMI reduction circuit of anembodiment of the invention;

FIG. 22 is a circuit diagram of a rectifier and a filter of anembodiment of the invention;

FIG. 23 is a circuit diagram of a PFC of an embodiment of the invention;

FIG. 24 is a circuit diagram of a power converter of an embodiment ofthe invention;

FIG. 25 is a circuit diagram of a bias generator of an embodiment of theinvention;

FIG. 26 is a circuit diagram of a bias generator of another embodimentof the invention;

FIG. 27 is a circuit diagram of a temperature detector of an embodimentof the invention; and

FIG. 28 is a circuit diagram of a temperature compensator of anembodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To make the present invention understandable and readable, the followingdisclosure will now be described in the following embodiments withreference to the drawings. The following descriptions of variousembodiments of this invention are presented herein for purpose ofillustration and giving examples only. It is not intended to beexhaustive or to be limited to the precise form disclosed. These exampleembodiments are just examples and many implementations and variationsare possible without the details provided herein.

FIG. 1 is a structural schematic view of an embodiment of the LED lampthe invention. FIG. 2 is a schematic cross-sectional view of the LEDlamp of FIG. 1. FIG. 3 is an exploded view of the LED lamp of FIG. 1. Asshown in the figures, the LED lamp includes a heat sink 1, a lamp shell2, a light board 3, a lamp cover 4 and a power source 5. In thisembodiment, the light board 3 is connected to the heat sink 1 byattachment for rapidly transferring heat from the light board 3 to theheat sink 1 when the LED lamp is working. Concretely, in someembodiments, the light board 3 is riveted to the heat sink 1. In someembodiments, the light board 3 is screwed to the heat sink 1. In someembodiments, the light board 3 is welded to the heat sink 1. In someembodiments, the light board 3 is adhered to the heat sink 1. In thisembodiment, the lamp shell 2 is connected to the heat sink 1, the lampcover 4 covers the light board 3 to make light emitted from the lightboard 3 pass through the lamp cover to project out. The power source 5is located in a chamber of the lamp shell 2 and the power source 5 is ECto the LED chips 311 for providing electricity.

As shown in FIG. 4, which is a schematic cross-sectional view of the LEDlamp. As shown in FIGS. 1, 2 and 4, the chamber of the lamp shell 2 ofthis embodiment is formed with a first heat dissipating channel 7 a. Anend of the first heat dissipating channel is formed with a first airinlet 2201. An opposite end of the lamp shell 2 is formed with a ventinghole 222 (at an upper portion of the lamp neck 22). Air flow into thefirst heat dissipating channel 2201 and flow out from the venting hole222 for bringing out heat in the first heat dissipating channel 7 a(primarily, heat of the working power source 5). As for the path of heatdissipation, heat generated from the heat-generating components of theworking power source 5 is transferred to air (around the heat-generatingcomponents) in the first heat dissipating channel 7 a by thermalradiation first, and then external air enters the first heat dissipatingchannel 7 a by convection to bring out internal air to make heatdissipation. In this embodiment, the venting hole 222 at the lamp neck22 can also make direct heat dissipation.

As shown in FIGS. 1, 2 and 4, a second heat dissipating channel 7 b isformed in the fins and the base 13 of the heat sink 1. The second heatdissipating channel 7 b has a second air inlet 1301. In this embodiment,the first air inlet 2201 and the second air inlet 1301 share the sameopening formed on the light board 3. This will be described more detaillater. Air flows from outside of the LED lamp into the second air inlet1301, passes through the second heat dissipating channel 7 b and finallyflows out from spaces between the fins 11 so as to bring out heat of thefins 11 to enhance heat dissipation of the fins 11. As for the path ofheat dissipation, heat generated from the LED chips is conducted to theheat sink 1, the fins 11 of the heat sink 1 radiate the heat tosurrounding air, and convection is performed in the second heatdissipating channel 7 b to bring out heated air in the heat sink 1 tomake heat dissipation.

As shown in FIGS. 1 and 4, the heat sink 1 is provided with a third heatdissipating channel 7 c formed between adjacent two of the fins 11 or ina space between two sheets extending from a single fin 11. A radialouter portion between two fins 11 forms an intake of the third heatdissipating channel 7 c. Air flows into the third heat dissipatingchannel 7 c through the radial outer portion of the LED lamp to bringout heat radiated from the heat sink 11 to air.

FIG. 5 is a perspective view of the LED lamp of the embodiment, whichshows assembling of the heat sink 1 and the lamp cover 4. FIG. 6 is astructural schematic view of FIG. 5 without the light output surface 43.As shown in FIGS. 5 and 6, in this embodiment, the lamp cover 4 includesa light output surface 43 and an end surface 44 with a vent 41. Airflows into both the first heat dissipating channel 7 a and the secondheat dissipating channel 7 b through the vent 41. When the LED chips 311(shown in FIG. 6) is illuminated, the light passes through the lightoutput surface 43 to be projected from the lamp cover 4. In thisembodiment, the light output surface 43 may use currently availablelight-permeable material such as glass, PC, etc. The term “LED chip”mentioned in all embodiments of the invention means all light sourceswith one or more LEDs (light emitting diodes) as a main part, andincludes but not limited to an LED bead, an LED strip or an LEDfilament. Thus, the LED chip mentioned therein may be equivalent to anLED bead, an LED strip or an LED filament. As shown in FIG. 5, in thisembodiment, the ratio of area of the light output surface 43 to area ofthe end surface 44 is 4˜7. Preferably, the ratio of area of the lightoutput surface 43 (area of a single side of the light output surface 43,i.e. area of surface of the side away from the LED chips 311) to area ofthe end surface 44 (area of a single side of the end surface 44, i.e.area of surface of the side away from the LED chips 311, including areaof the vent 41) is 5˜6. More preferably, the ratio of area of the lightoutput surface 43 to area of the end surface 44 is 5.5. The end surface44 is used for allowing air to pass to enter both the first heatdissipating channel 7 a and the second heat dissipating channel 7 b. Thelight output surface 43 allows light from the light source to output. Asa result, a balance can be accomplished between the light output and theheat dissipation. In this embodiment, to satisfy the requirement of airintake of both the first heat dissipating channel 7 a and the secondheat dissipating channel 7 b, the ratio of area of the lamp cover 4 toarea of the end surface 44 is 6˜7. As a result, a balance can beaccomplished between the light output and air required by the heatdissipation.

As shown in FIGS. 5 and 6, in this embodiment, an inner reflectingsurface 4301 is disposed inside the light output surface 43 of the lampcover 4. The inner reflecting surface 4301 is disposed in the innercircle of the array of LED chips 311. In an embodiment, an outerreflecting surface 4302 is disposed in the outer circle of the array ofLED chips 311. The outer reflecting surface 4302 corresponds to the LEDchips 311 on the light board 3. The arrangement of both the innerreflecting surface 4301 and the outer reflecting surface 4302 is usedfor adjusting a light emitting range of the LED chip set 31 to make thelight concentrated and to increase brightness in a local area. In otherwords, under the condition of the same luminous flux, illuminance of theLED lamp can be increased. In the concrete, all the LED chips 311 inthis embodiment are mounted on the bottom side of the light board 3 (ina using status). In other words, the LED lamp of the present embodimentdo not emit lateral light from the LED chips 311. When working, theprimary light emitting surface of the LED chips 311 are completelydownward. At least 60% of the light from the LED chips 311 are emittedthrough the light output surface 43 without reflection. As a result, incomparison with those LED lamps with lateral light (the lateral light isreflected by a cover or a lampshade to be emitted downward, and intheory there must be part of light loss in the process of reflection.)The LED chips 311 in this embodiment possess better light emittingefficiency. In other words, under the condition of the same lumen value(luminous flux), the LED lamp in the present embodiment possesses higherilluminance. And the emitted light can be concentrated to increaseilluminance in a local area by the arrangement of both the innerreflecting surface 4301 and the outer reflecting surface 4302, forexample, in an area under the LED lamp between 120 degrees and 130degrees (a light emitting range under the LED lamp between 120 degreesand 130 degrees). When the LED lamp is installed at a relatively highposition, in the same angular range of light emitting, the lit area ofthe LED lamp still satisfies the requirement and illuminance in thisarea can be higher. FIG. 7 is a schematic view of light transmission ofthis embodiment and FIG. 8 is a light pattern of FIG. 7. As shown inFIGS. 5-8, in the aspect of the light emitting effect, in the projectedarea of the LED lamp, i.e. the projected area M under the LED lamp,there is a light concentrating area m within the projected area M, theLED lamp including the reflecting surface reflects at least part oflight from the LED chips 311 onto the light concentrated area m toincrease brightness of the light concentrated area m. The reflectingsurface includes the inner reflecting surface 4301 and the outerreflecting surface 4302. Both the inner reflecting surface 4301 and theouter reflecting surface 4302 reflect at least part of light from theLED chips 311 onto the light concentrated area m. Preferably, in thisembodiment, at least 5% of luminous flux of the light source isreflected to pass through the light output surface 43. In practice,total luminous flux of the light reflected by both the inner reflectingsurface 4301 and the outer reflecting surface 4302 and emitted throughthe light output surface 43 is at least 1000 Im. Preferably, totalluminous flux of the light reflected by both the inner reflectingsurface 4301 and the outer reflecting surface 4302 and emitted throughthe light output surface 43 is at least 1500 Im. Total luminous flux ofthe light reflected by the outer reflecting surface 4302 is greater thanthat of the light reflected by the inner reflecting surface 4301. Thisshows that, about the problem of glare resulting from an LED lamp withhigh lumen, disposing the outer reflecting area 4302 can reflectconsiderable part of lateral luminous flux. This can significantlyreduce the glare. In this embodiment, the light concentrated area m isan annular region. In this embodiment, a center angle between an inneredge of the light concentrated area m and an axis of the LED lamp is 20degrees, and a center angle between an outer edge of the lightconcentrated area m and an axis of the LED lamp is 50 degrees. In thisembodiment, luminous flux of the light projected by the LED lamp ontothe light concentrated area m accounts for 35%˜50% of the total luminousflux, so that the light concentrated area m possesses a better lightingeffect. In addition, by the arrangement of both the inner reflectingsurface 4301 and the outer reflecting surface 4302, not only can thelateral light be reduced to prevent glare, but also at least part oflight from the LED chips 311 can be reflected onto the projected area Mto enhance illuminance in the projected area M.

The inner reflecting surface 4301 is used for reflecting part of lightemitted from the inmost LED chips 311 of the LED chip set 31. The outerreflecting surface 4302 is used for reflecting part of light emittedfrom the outermost LED chips of the LED chipset 31. The outermost LEDchips 311 are greater than the inmost LED chips 311 in number. The outerreflecting surface 4302 is greater than the inner reflecting surface4301 in area. Because the outermost portion of the LED chip set 31includes more LED chips than the inmost portion, larger reflecting areais required to regulate light output.

In this embodiment, the inner reflecting surface 4301 and the outerreflecting surface 4302 have first area A1 and second area A2,respectively. The LED chips 311 in the outermost portion of the LED chipset 31 and in the inmost portion of the LED chip set 31 are N1 and N2 innumber, respectively. Their relationship is:(A1/N1):(A2/N2)=0.4˜1

When the ratio of area of the inner reflecting surface 4301corresponding to a single LED chip 311 in the inmost portion of the LEDchip set 31 to area of the outer reflecting surface 4302 correspondingto a single LED chip 311 in the outermost portion of the LED chip set 31falls in the above range, both the LED chips 311 in the inmost portionof the LED chip set 31 and the LED chips 311 in the outermost portion ofthe LED chip set 31 have a better effect of light output.

As shown in FIG. 2, in this embodiment, the inner reflecting surface4301 is lower than the outer reflecting surface 4302 in height. Theheight means a height of each of the both in an axis of the LED lamp. Bythe configuration of the inner reflecting surface 4301 being lower thanthe outer reflecting surface 4302 in height, decrease of a lightdistribution under the LED lamp can be avoided and a central portion ofthe light distribution region of the LED lamp can be prevented to be adark part. In this embodiment, height of the outer reflecting surface4302 in the axis of the LED lamp is not greater than 20 mm. Preferably,height of the outer reflecting surface 4302 in the axis of the LED lampis not greater than 15 mm. On the other hand, to control overall heightof the LED lamp, height of the outer reflecting surface 4302 accountsfor not over 9% of overall height of the LED lamp. Preferably, height ofthe outer reflecting surface 4302 accounts for not over 6% of overallheight of the LED lamp. As for functions of the outer reflecting surface4302, height of the outer reflecting surface 4302 has to account forabove 2% of overall height of the LED lamp. Preferably, height of theouter reflecting surface 4302 accounts for above 3% of overall height ofthe LED lamp. In other words, comprehensively considering control ofheight of the LED lamp and functions of reflection, light concentration,anti-glare, etc., it is necessary that height of the outer reflectingsurface 4302 accounts for 2%˜9% of overall height of the LED lamp.Preferably, height of the outer reflecting surface 4302 accounts for3%˜6% of overall height of the LED lamp.

As shown in FIG. 9, a diameter of a maximum inscribed circle of the vent41 is less than 2 mm, preferably, 1.0˜1.9.mm. As a result, both bugs andmost dust can be resisted, and venting efficiency of the vent 41 can bekept great enough. In other words, alternatively, the vent 41 definesboth a length direction and a width direction, i.e. the vent has alength and a width, and the length is greater than the width. Thelargest width of inscribed circle of the vent 41 is less than 2 mm. Inan embodiment, the largest width is from 1 mm to 1.9 mm. In addition,the largest width of the vent 41 is greater than 1 mm. If the width ofthe vent 41 is less than 1 mm, then more pressure is required to pushair to enter the vent 41, which is advanced for venting.

FIGS. 10A˜10G show shapes of some embodiments of the vent 41. As shownin FIGS. 10A˜10G, the vent 41 may be circular, strip-shaped, arced,trapezoidal, diamond or their combination. As shown in FIG. 10A, whenthe vent 41 is configured to be circular, its diameter must be less than2 mm to resist bugs and most dust and venting efficiency of the vent 41can be kept great enough. As shown in FIGS. 10B and 100, when the vent41 is configured to be strip-shaped or arced, its width must be lessthan 2 mm to accomplish the above effects. As shown in FIG. 10D, whenthe vent 41 is configured to be trapezoidal, its lower base must be lessthan 2 mm to accomplish the above effects. As shown in FIG. 10E, whenthe vent 41 is configured to be roundcornered rectangular, its widthmust be less than 2 mm to accomplish the above effects. As shown inFIGS. 10F and 10G, when the vent 41 is configured to be triangular ordrop-shaped, a diameter of its maximum inscribed circle must be lessthan 2 mm.

In some embodiments, the vent 41 on the end surface 44 is multiple innumber. For example, the vents 41 may be annularly arranged on the endsurface 44 for even air intake. The vents 41 may also be radiallyarranged on the end surface 44. The vents 41 may also be irregularlyarranged.

In some embodiments, in an axial direction of the LED lamp, the ventsmay be inclined to an axis of the LED lamp. In other words, an angle isformed between an axis of the vent 41 and the axis of the LED lamp. Asshown in FIG. 10H, axes of at least part of the vents 41 are inclined tothe axis of the LED lamp, and the inclined directions of the part ofvents 41 are toward the first air inlet 2201 of the first heatdissipating channel 7 a. Thus, after air passes the part of vents 41, itwill flow to the first air inlet 2201 of the first heat dissipatingchannel 7 a to perform convection for allowing more air to flow into thefirst heat dissipating channel 7 a to dissipate heat from the powersource 6 therein. As shown in FIG. 10I, axes of at least part of thevents 41 are inclined to the axis of the LED lamp, and the inclineddirections of the part of vents 41 are toward the second air inlet 1301of the second heat dissipating channel 7 b. Thus, after air passes thepart of vents 41, it will flow to the second air inlet 1301 of thesecond heat dissipating channel 7 b to perform convection for allowingmore air to flow into the second heat dissipating channel 7 b todissipate heat from the heat sink 1 therein.

In FIG. 10A, there are two broken lines on the end surface 44. The innerbroken line represents a position the first air inlet 2201 (as shown inFIG. 2) is projected onto the end surface 44. The region within theinner broken line is defined as a first portion (first opening region433). The region between the inner circle and the outer circle isdefined as a second portion (second opening region 434). In thisembodiment, the first air inlet 2201 is projected onto the end surfacein an axis of the LED lamp to occupy an area on the end surface 44, itis the first portion (first opening region 433). The other area on theend surface 44 is the second portion (second opening region 434). Thevent 41 in the first portion is greater than the vent 41 in the secondportion in area. Such an arrangement is advantageous to making most airflow into the first heat dissipating channel 7 a for better effect ofheat dissipation to the power source 5 and reduction of rapidly aging ofelectronic components of the power source 5. These features are alsoavailable to the vent 41 in other embodiments.

In other embodiments, the first air inlet 2201 is projected onto the endsurface 44 in an axis of the LED lamp to occupy an area on the endsurface 44, it is the first portion (first opening region 433). Theother area on the end surface 44 is the second portion (second openingregion 434). The vent 41 in the first portion is greater than the vent41 in the second portion in area. As a result, heat of the fins 11 canbe better dissipated to perform better heat dissipation to the LED chips311 and prevent a region around the LED chips 311 from forming hightemperature. In detail, area of both the first portion and the secondportion can be selected according to actual requirements.

In some applications, there may be a limit of overall weight of an LEDlamp. For example, when an LED lamp adopts an E39 head, its maximumweight limit is 1.7 Kg. Thus, besides the fundamental elements such as apower source, a lamp cover and a lamp shell, in some embodiments, weightof a heat sink is limited within 1.2 Kg. For some high-power LED lamps,the power is about 150 W˜300 W, and their luminous flux can reach 20000lumens to 45000 lumens. That is, under a limit of weight, a heat sinkmust dissipate heat from an LED lamp with 20000˜45000 lumens. Under acondition of heat dissipation of natural convection, usually power of 1W needs area of heat dissipation of at least 35 square cm. The followingembodiments intend to reduce area of heat dissipation for power of 1 Wunder guarantee of a receiving space of the power source 5 and effect ofheat dissipation. Under a precondition of weight limit of the heat sink1 and limit of the power source 5, the best effect of heat dissipationcan be accomplished.

As shown in FIGS. 1 and 2, in this embodiment, the LED lamp includespassive heat dissipating elements which adopt natural convection andradiation as a heat dissipating manner without any active heatdissipating elements such as a fan. The passive heat dissipating elementin this embodiment includes a heat sink 1 composed of fins 11 and a base13. The fins 11 radially extend from and connect to the base 13. Whenusing the LED lamp, at least part of heat from the LED chips 311 isconducted to the heat sink 1 by thermal conduction. At least part ofheat occurred from the heat sink 1 is transferred to external air bythermal convection and radiation. A diameter of a radial outline of theheat sink 1, in a hanging status as shown in the figures, upward tapersoff or is substantially in a taper shape for a better match with alampshade.

As shown in FIGS. 2,4 and 5, a gap is kept between the end side 44 andthe light board 3 to form a room 8. The room 8 communicates with boththe first air inlet 2201 of the first heat dissipating channel 7 a andthe second air inlet 1301 of the second heat dissipating channel 7 b.Air flows into the room 8 through the vent 41 of the end side 44 andthen flows into both the first heat dissipating channel 7 a and thesecond heat dissipating channel 7 b. The room 8 allows air therein tomix and the mixed air is distributed according to negative pressure(resulting from temperature difference) of both the first and secondheat dissipating channels 7 a, 7 b so as to make distribution of airmore reasonable.

In this embodiment, when a passive heat dissipation manner (fanless) isadopted, the ratio of power (W) of the LED lamp to heat dissipating area(square cm) of the heat sink 1 is 1:20˜30. That is, each watt needs heatdissipating area of 20˜30 square cm for heat dissipation. Preferably,the ratio of power of the LED lamp to heat dissipating area of the heatsink 1 is 1:22˜26. More preferably, the ratio of power of the LED lampto heat dissipating area of the heat sink 1 is 1:25. The first heatdissipating channel 7 a is formed in the lamp shell 2, the first heatdissipating channel 7 a has the first air inlet 2201 at an end of thelamp shell 2, and another end of the lamp shell 2 has the venting hole222. Air flows into the first air inlet 2201 and flows out from theventing hole 222 to bring out heat in the first heat dissipating channel7 a. The second heat dissipating channel 7 b is formed in the fins 11and the base 13 and the second heat dissipating channel 7 b has thesecond air inlet 1301. Air flows into the second air inlet 1301, passesthe second heat dissipating channel 7 b, and finally flows out from thespaces between the fins 11 to bring out heat radiated from the fins 11to air therearound and enhance heat dissipation of the fins 11. By boththe first and second heat dissipating channels 7 a, 7 b, efficiency ofnatural convection can be increased. This reduces required area of heatdissipation of the heat sink 1 so as to make the ratio of power of theLED lamp to heat dissipating area of the heat sink 1 be between 20 and30. In this embodiment, overall weight of the LED lamp is less than 1.7Kg. When the LED lamp is provided with power of about 200 W (below 300W, preferably, below 250 W), the LED chips 311 are lit up and emitluminous flux of at least 25000 lumens.

As shown in FIG. 1, weight of the heat sink 1 in this embodimentaccounts for above 50% of weight of the LED lamp. In some embodiments,weight of the heat sink 1 accounts for 55˜65% of weight of the LED lamp.Under this condition, volume of the heat sink 1 accounts for above 20%of volume of the overall LED lamp. Under a condition of the same thermalconductivity of the heat sink 1 (i.e. overall heat sink 1 uses a singlematerial or two different materials with almost identical thermalconductivity), the larger the volume occupied by the heat sink 1 is, thelarger the heat dissipating area which can be provided by the heat sink1 is. As a result, when volume of the heat sink 1 accounts for above 20%of volume of the overall LED lamp, the heat sink 1 may have more usablespace to increase its heat dissipating area. Considering the arrangementspace of the power source 5, the lamp cover 4 and the lamp shell 2,preferably, volume of the heat sink 1 accounts for 20%˜60% of volume ofthe overall LED lamp. More preferably, volume of the heat sink 1accounts for above 25˜50% of volume of the overall LED lamp.Accordingly, although the overall size of the LED lamp is limited andthe space for receiving the power source 5, the lamp cover 4 and thelamp shell 2 must be kept, volume of the heat sink 1 can still bemaximized. This is advantageous to design of overall heat dissipation ofthe LED lamp.

FIG. 13 is top view of the heat sink 1 of the LED lamp of theembodiment. As shown, the heat sink 1 suffers the above volume limit, soat least part of the fins 11 are extended outward in a radial directionof the LED lamp with at least two sheets at an interval. By such anarrangement, the fins 11 in a fixed space can have larger area of heatdissipation. Besides, the extended sheets forms support to the fins 11to make the fins firmly supported on the base 13 to prevent the fins 11from deflecting.

In detail, as shown in FIG. 13, the fins includes first fins 111 andsecond fins 112. The bottoms of both the first fins 111 and the secondfins 112 in an axis of the LED lamp connect to the base 13. The firstfins 111 interlace with the second fins 112 at regular intervals. Beingprojected from the axial direction of the LED lamp, each of the secondfins 112 is of a Y-shape. Such Y-shaped second fins 112 can have moreheat dissipating area under a condition of the heat sink 1 occupying thesame volume. In this embodiment, both the first fins 111 and the secondfins are evenly distributed on a circumference, respectively. Everyadjacent two of the second fins 112 are symmetrical about one of thefirst fins 111. In this embodiment, an interval between one of the firstfins 111 and adjacent one of the second fins 112 is 8˜12 mm. In general,to make air flow in the heat sink 1 smooth and to make the heat sinkperform a maximum effect of heat dissipation, intervals between the fins11 should be as uniform as possible.

FIG. 17 is a main view of an LED lamp of another embodiment. As shown,two side of each fin 11 is provided with heat dissipating bars 16. Eachof the heat dissipating bar 16 on a side is located between adjacent twoof the heat dissipating bars on the other side. That is, the heatdissipating bars 16 on two opposite sides do not superpose each other ina projective direction. In this embodiment, a distance between every twoof the heat dissipating bars on a side is the same as a distance betweenevery two of the heat dissipating bars on the other side. Such heatdissipating bars 16 can increase overall surface area of the fins 11 tomake the fins 11 have more heat dissipating area for heat dissipationfor improving performance of heat dissipation of the heat sink 1. Inthis embodiment, to increase surface area of the fins 11, surfaces ofthe fins 11 may be configured to be of a waved shape.

As shown in FIG. 13, at least one of the fins 11 is divided into twoportions in a radial direction of the LED lamp. Thus, a gap between thetwo portions forms a passage to allow air to pass. In addition, theprojecting area of the gap directly exactly corresponds to an area thatthe LED chips 311 are positioned on the LED board 3 to enhanceconvection and improve an effect of heat dissipation to the LED chips311. In an aspect of limited overall weight of the LED lamp, part of thefins 11 divided with a gap reduces the amount of the fins 11, decreasesoverall weight of the heat sink 1, and provides a surplus space toaccommodate other elements. In this embodiment, as shown in

FIG. 14 is an enlarged view of portion E in FIG. 13. As shown in FIGS.13 and 14, the fins 11 includes first fins 111 and second fins 112. Eachof the first fins 11 is divided into two portions in a radial directionof the LED lamp, i.e. a first portion 111 a and a second portion 111 b.The two portions are divided with a gap portion 111 c. The first portion111 a is located inside the second portion 111 b in a radial direction.Each of the second fins 112 has a third portion 112 a and a fourthportion 112 b extending therefrom. The fourth portions 112 b are locatedradially outside the third portions 112 a to increase space utilizationand make the fins have more heat dissipating are for heat dissipation.As shown in FIG. 14, the third portion 112 a is connected to the fourthportion 112 b through a transition portion 113. The transition portion113 has a buffer section 113 a and a guide section 113 b. At least oneof both of the buffer section 113 a and the guide section 113 b arearced in shape. In other embodiment, both the buffer section 113 a andthe guide section 113 b are formed into an S-shape or an invertedS-shape. The buffer section 113 a is configured to prevent air radiallyoutward flowing along the second fins 112 from being obstructed to causevortexes. Instead, the guide section 113 b is configured to be able toguide convection air to radially outward flow along the second fins 112without interference (as shown id FIG. 15).

As shown in FIG. 14, one of the second fins 112 includes a third portion112 a and two fourth portions 112 b. The two fourth portions 112 b aresymmetrical about the third portion 112 a. In other embodiments, one ofthe second fins 112 may include a third portion 112 a and multiplefourth portions 112 b such as three or four fourth portions 112 b (notshown). The multiple fourth portions 112 b of the second fin 112 arelocated between two first fins 111.

As shown in FIG. 14, a direction of any tangent of the guide section 113b is separate from the gap portion 111 c to prevent convection air fromflowing into the gap portion 111 c through the guide portion 113 b, suchthat the poor efficiency of heat dissipation caused by longer convectionpaths is able to be avoid as well. Preferably, a direction of anytangent of the guide section 113 b is located radially outside the gapportion 111 c. In other embodiments, a direction of any tangent of theguide section 113 b is located radially inside the gap portion 111 c.

As shown in FIG. 16, in another embodiment, a direction of any tangentof the guide section 113 b falls in the gap portion 111 c to makeconvection more sufficient but convection paths will increase.

As shown in FIG. 11, at least partially of fin 11 has a protrusion 1102projecting from a surface of the fin 11. The protrusions 1102 extendalong an axis of the LED lamp and are in contact with the base 13.Besides, a surface of the protrusion 1102 may selectively adopt acylindrical shape or a regular or an irregular polygonal cylinder. Theprotrusions 1102 increase surface area of the fins 11 to enhanceefficiency of heat dissipation. In addition, the protrusions 1102 alsoform a support effect to the fins 11 to prevent the fins 11 from beinginflected in manufacture. In some embodiments, a single fin 11 isdivided into two portions in a radial direction of the LED lamp. Eachportion is provided with at least one protrusion 1102 to support the twoportions. In this embodiment, the protrusion 1102 is located at an endportion of each fin 11 in a radial direction of the LED lamp, forexample, at end portions of the first portions 111 a, 111 b (the endsnear the gap portion 111 c).

In some embodiments, when each fin 11 is a single piece without the gapportion, the protrusion 1102 may also be disposed on a surface of eachfin 11 (not shown) to increase surface area of heat dissipation of thefins 11 and have a support effect to the fins 11 to prevent the fins 11from being inflected in manufacture.

FIG. 12 is a cross-sectional view of the LED lamp of this embodiment. Asshown, in this embodiment, a back side 134 of the base 13 is slanted.For example, when the LED lamp is being hung, in an inward radialdirection, the back side 134 is upwardly slanted. In another aspect, ina radial direction of the LED lamp toward an axis of the LED lamp, anaxial distance from the back side 134 to the light board 3 isprogressively increased. Such an arrangement is advantageous toconvection air is introduced along the back side 134 to bring out heatof the back side 134 and prevents the back side 134 from obstructing airflowing into.

As shown in FIGS. 1 and 18, the light board 3 has an inner border 3002and an outer border 3003. Both the inner border 3002 and the outerborder 3003 separately upward extend along the axial direction of theLED lamp to form a region. Area of part of the fins 11 inside the regionis greater than area of part of the fins 11 outside the region. As aresult, the most of the fins 11 can correspond to the light board 3 (ashorter heat dissipating path) to enhance heat dissipating efficiency ofthe fins 11 and increase effective area of heat conduction of the fins11 to the LED chips 311.

As shown in FIGS. 3, 5 and 18, a reflecting region 3001 is disposed in aregion between the inner ring and an outer edge of the light board 3 toreflect the upward light to the light output surface 43. This can reduceloss of light in an opposite direction of light output in the axialdirection of the LED lamp to increase overall intensity of light output.

As shown in FIGS. 4 and 18, the light board 3 is formed with a thirdaperture 32 separately communicating with the first heat dissipatingchannel 7 a and the second heat dissipating channel 7 b. That is, thethird aperture 32 communicates with spaces between the fins 11 and thechamber of the lamp shell 2 to form air convection paths between thespaces between the fins 11 and between the chamber of the lamp shell 2and the outside of the Led lamp. The third aperture 32 is located insidethe inner ring of the LED lamp. Thus, it would not occupy the space ofthe reflecting region 3001 to affect reflective efficiency. In detail,the third aperture 32 is located at a central region of the light board3 and both the first air inlet 2201 and the second air inlet 1301 makeair intake through the same aperture (the third aperture 32). In otherwords, after convection air passes through the third aperture 32, andthen enters the first air inlet 2201 and the second air inlet 1301. Thethird aperture 32 is located at a central region of the light board 3,so both the first air inlet 2201 and the second air inlet 1301 cancommonly use the same air intake. Thus, this can prevent from occupyingexcessive region of the light board 3 and prevent usable regional areaof the light board 3 for disposing the LED chips 311 from decreasing dueto multiple air intakes. On the other hand, the sleeve 21 corresponds tothe third aperture 32, so convection air may have an effect of thermalisolation to prevent temperatures inside and outside the sleeve 21 frommutually affecting each other when air enters. In other embodiments, ifboth the first air inlet 2201 and the second air inlet 1301 are locatedat different positions, then the third aperture 32 may be multiple innumber to correspond to both the first air inlet 2201 and the second airinlet 1301. The light board 3 comprises a first surface and a secondsurface which is opposite to the first surface, the LED chips 311 aremounted on the first surface and surrounding the third aperture 32, andthe second surface is in contact with the base 13 of the heat sink 1,such that heat generated from the LED chips 311 is able to betransferred to the fins 11 through the base 13 while the LED lamp isworking

As shown in FIGS. 1, 2, 3 and 4, the lamp shell 2 includes the lamp head23, the lamp neck 22 and the sleeve 21. The lamp head 23 connects to thelamp neck 22 which connects to the sleeve 21. The sleeve 21 is locatedin the heat sink 1 (in the axial direction of the LED lamp, all or mostof the sleeve 21, for example, at least 80% of height of the sleeve 21,does not exceed the heat sink 1). The lamp neck 22 projects from theheat sink 1. Both the sleeve 21 and the lamp neck 22 can providesufficient space to receive the power source 5 and perform heatdissipation, especially for the power source 5 of a high power LED lamp(in comparison with a low power LED lamp, a power source of a high powerLED lamp has more complicated composition and larger size). The powersource 5 is received in both the lamp neck 22 and lamp head 23. Totalheight of the lamp neck 22 and the lamp head 23 is greater than heightof the heat sink 1 so as to provide more space for receiving the powersource 5. The heat sink 1 is separate from both the lamp neck 22 and thelamp head 23 (not overlap in the axial direction, the sleeve 21 isreceived in the heat sink 1). Thus, the power source 5 in both the lampneck 22 and the lamp head 23 is affected by the heat sink 1 slightly(heat of the heat sink 1 would not be conducted to the lamp neck 22 andthe lamp head 23 along a radial direction). In addition, theconfiguration of height of the lamp neck 22 is advantageous to thechimney effect of the first heat dissipating channel 7 a to guaranteeconvection efficiency of the first heat dissipating channel 7 a. Inother embodiments, height of the lamp neck 22 is at least 80% of heightof the heat sink 1 to accomplish the above function. The sleeve 21 ismade of a thermo-isolated material to prevent mutual influence of heatfrom the fins and the power source.

As shown in FIG. 2, the second air inlet 1301 is located in a lowerportion of the heat sink 1 and radially corresponds to an inner side orthe inside of the heat sink 1, i.e. the second air inlet 1301 radiallycorresponds to the inner side or the inside of the fins 11. The innerside or the inside of the fins 11 corresponds to an outer wall (aradially inner side of the fins 11, which nears or abuts against thesleeve 21) of the sleeve 21 of the lamp shell 2. Thus, after convectionair flows into the second air inlet 1301, it flows upward along theouter wall of the sleeve 21 to perform convection and radiallydissipates heat in the inner side or the inside of the fins 11 and theouter wall of the sleeve 21 to implement an effect of thermal isolation.That is, this can prevent heat of the heat sink 1 is conducted from theouter wall of the sleeve 21 to the inside of the sleeve 21 not to affectthe power source 5. From the above, the second heat dissipating channel7 b can not only enhance heat dissipation of the fins 11, but alsoimplement an effect of thermal isolation. Make a positional comparisonbetween the second air inlet 1301 and the LED chips 311, the second airinlet 1301 is located radially inside all of the LED chips 311.

FIGS. 19A˜19C are perspective views of the power source 5 of oneembodiment at different viewpoints. FIG. 19d is a main view of the powersource 5 of one embodiment. The power source 5 is electrically connectedto the LED chips 311 to power the LED chips 311. As shown in FIGS.19A˜19C, the power source 5 includes a power board 51 and a plurality ofelectronic components mounted thereon.

As shown in FIGS. 20 to 28, the present disclosure provides a powersupply module for LED lamp. The power supply module includes input ends(ACN, ACL) for receiving AC driving signal; a first rectifying circuit100 for converting the AC driving signal into rectified signal; afiltering 200 for converting the rectified signal into filtered signal;a power converter 400 for converting the filtered signals into powersignal which is capable of lighting up an LED light source 500; and abias generating circuit 600 electrically connected to the input ends(ACN, ACL) and the power converter 400 for performing buck-conversion tothe AC driving signal to generate a working voltage of the powerconverter 400.

In this embodiment, the first rectifying circuit 100 may be a bridgerectifier. As shown in FIG. 22, which is a circuit diagram of arectifying circuit and a filtering circuit of an embodiment of theinvention, the first rectifying circuit 100 includes diodes D7, D8, D9and D10. The first rectifying circuit 100 performs full waverectification to the AC driving signal to generate DC driving signal (DCpower).

In detail, as shown in FIG. 22, anodes of diodes D7, D9 are electricallyconnected to a first end of the filtering circuit 200, cathodes ofdiodes D7, D9 are electrically connected to anodes of diodes D8, D10,and cathodes of diodes D8, D10 are electrically connected to a secondend of the filtering circuit 200. Contacts of diodes D7 and D8 areelectrically connected to the first end ACL. A cathode of diode D8 iselectrically connected to a cathode of diode D10. Contacts of diodes D9and D10 are electrically connected to the second end ACN.

In this embodiment, the filtering circuit 200 includes capacitors C1, C2and an inductor L1. First ends of both capacitor C1 and inductor L1serve as the second end of the filtering circuit 200 to electricallyconnect with cathodes of diodes D8 and D10. The second end of inductorL1 is electrically connected to the first end of capacitor C1. Thesecond ends of capacitors C1 and C2 serve as the first end of thefiltering circuit 200 to electrically connect with anodes of diodes D7and D9. The filtering circuit 200 receives the DC power (the rectifiedsignal) rectified by the first rectifying circuit 100 and filters highfrequency components of the DC power. The DC power filtered by thefiltering circuit 200 is a relatively flat DC waveform. The filteredsignal is sent to a post-stage circuit through connecting ends 301 and302.

An electro-magnetic interference (EMI) reduction circuit 900 may bedisposed between the input ends (ACN, ACL) and the rectifying circuit100. The EMI reduction circuit 900 can reduce influence to the drivingsignal from an interference magnetic field. In the EMI reduction circuit900, a power line (including a main line and/or a branch of the mainline) electrically connected to two ends of the input ends ACN, ACL iselectrically connected with an excitation coil LF2 connecting a resistorbranch (e.g. a branch at which resistor R1 is located) and capacitorbranches (e.g. branches at which capacitors CX1, CX2, CX3 are located),and separately electrically connecting inductor Li1, Li2 at twobranches.

In this embodiment, the power converter 400 converts the filtered signalinto an electrical signal which is capable of lighting up the LED lightsource 500. The power converter 400 may change voltage level of thefiltered signal to generate DC driving signal with target voltage value.The power converter 400 has an output end for outputting DC drivingsignal with target voltage values.

FIG. 24 is a circuit diagram of a power converter of an embodiment ofthe invention. As shown in FIGS. 20 and 24, the power converter 400receives signal from a pre-stage circuit through the connecting end 401,402, and the power signal are provided to a post-stage through theconnecting ends 5001, 5002. The power converter 400 may adopt a PWM(Pulse Width Modulation) circuit, which controls pulse width to outputtarget signal. In detail, the power converter 400 includes a controllerU2, a power switch Q2, a transformer T2 and a diode D10. Controller U2,power switch Q2, diode D10 and an energy storage coil (a coil of thetransformer T2, which is electrically connected between the power switchQ2 and the connecting end 5002) cooperate to output power signal (DCdriving signal) with required voltage and/or current. The controller U2is activated by a working voltage VCC provided by the bias generatingcircuit 600 to output PWM control signal to control switching of thepower switch Q2, so that the energy storage coil repeatedly charge anddischarge in response to the switching state of power switch and thecontinuity of the current can be maintained through diode D4 (which isoperated as a flyback diode), and thus generate the required powersignal between the connecting ends 5001, 5002.

Power switch Q2 may be a MOSFET. A first end (power end) of controllerU2 electrically connects to an output end of the bias generating circuit600. A second end of controller U2 electrically connects to an end oftransformer T2. An end of the energy storage coil of transformer T2electrically connects to a negative end (i.e. connecting end 5002) ofthe DC output ends and the other end thereof electrically connects to ananode of diode D4. An anode of diode D4 electrically connects to apositive end (i.e. the connecting end 5001) of the DC output ends. Anend of the induction coil of transformer T2 electrically connects to asecond end of controller U2 and the other end of the induction coil isgrounded. A third end of controller U2 electrically connects to acontrol end of power switch Q2 through resistor R9. A first end of powerswitch Q2 electrically connects to a connecting point between diode D4and transformer T2, and a second end of power switch Q2 connects to afourth end of controller U2. Power converter 400 may be further providedwith a sampling circuit to sample its working status and serve as areference of output signal of the controller U2.

For example, the sampling circuit includes resistors R8, R10, capacitorC6 and an induction coil of the transformer T2. The controller U2 maysample voltage of the main line from resistor R8 and capacitor C6through its first end, sample output current from the induction coilthrough its second end and sample current flowing through the powerswitch Q2 from an end of resistor R10 through its fourth end.Configuration of the sampling circuit is related to the control mannerof the controller U2, the invention is not limited to this embodiment.

In this embodiment, at least one end of the switch controller U3electrically connects to a branch at which inductor L2 is located. Afiltering element and/or current stabilizer may be added between theswitch controller and the inductor. The present invention is not limitedthereto.

To reduce both influence resulting from harmonic to circuit propertiesand conversion loss, a power factor correction (PFC) circuit 300 may bedisposed between the power converter 400 and filtering circuit 200. ThePFC circuit 300 can increase power factors of the filtered signal byadjusting signal properties (e.g. phase, level or frequency) of thefiltered signal. PFC circuit 300 electrically connects to an output endof bias generating circuit 600. In detail, PFC circuit 300 may be anactive PFC circuit.

FIG. 23 is a circuit diagram of a PFC circuit of an embodiment of theinvention. As shown in FIG. 23, PFC circuit 300 receives signal from thefiltering circuit 300 through the connecting ends 301, 302 and sendscorrected signal to the post-stage power converter 400 throughconnecting ends 401, 402. PFC circuit 300 includes a controller U1, apower switch Q1 electrically connected to controller U1, a transformerT1 and a diode D3. Power switch Q1 may be a MOSFET. A first end (powerend) of the controller U1 electrically connects to an output end 607 ofbias generating circuit 600. A second end of controller U1 electricallyconnects to an end of transformer T1. A coil of transformer T1electrically connects to a main branch in series. The other end of thecoil electrically connected to a second end of controller U1 isgrounded. A positive end (also called connecting end 5001) of the DCoutput ends electrically connects to the main branch. Diode D3 iselectrically connected in the branch in series. An anode of diode D3electrically connects to both an end of transformer T1 and the filteringcircuit 200, and a cathode thereof electrically connects to connectingend 401 for electrically connecting to both power converter 400 andconnecting end 5001. A third end of controller U1 electrically connectsto power switch Q1. An end of power switch Q1 electrically connects to afifth electrically connecting point between diode D3 and transformer T1.Controller U1 may further electrically connects to a sampling circuit (aconnecting point between resistor R2 and capacitor C3 electricallyconnects to the controller U1, and capacitor C3 electrically connects toresistor R3 in parallel) and other circuits as shown in FIG. 23.

It should be noted that, the PFC circuit may have various implementarymanners or circuit configurations, all which can be applied to theinvention, so they would not be described here.

FIG. 25 is circuit diagram of a bias generating circuit of the firstembodiment of the invention. As shown in FIGS. 21 and 25, biasgenerating circuit 600 a may include an electricity obtainer 610, aswitch controller U3 and an energy storage flyback unit 630. Electricityobtainer 610 electrically connects to both the input ends (ACN, ACL) andswitch controller U3. Switch controller U3 electrically connects toenergy storage unit 630 having an output end 607 for outputting aworking voltage (VCC). Output end 607 electrically connects to powerconverter 400 to provide the working voltage (VCC) to the powerconverter 400.

Switch controller U3 controls switching frequency of the energy storageunit 630 according to an electricity obtaining signal from theelectricity obtainer 610 to generate the working voltage of the powerconverter 400 and uses the output end 607 to output the working voltageto the power converter 400. The switch controller U3 is activated byresponding to the electricity obtaining signal from the electricityobtainer 610 and repeatedly switches on and off to periodically chargeand discharge by controlling conducting time of the energy storage unit630. And diode D5 is used to keep flyback. Thus, the working voltage ofthe power converter 400 is formed and is output to the power converter400 through the output end 607.

In an embodiment, the electricity obtainer 610 can convert AC drivingsignal into DC electricity obtaining signal which are equal to the ACdriving signal. As shown in FIGS. 21 and 25, electricity obtainer 610can be implemented by a second rectifying circuit (hereinafter “secondrectifying circuit 610”). Second rectifying circuit 610 includes a firstdiode D1 and a second diode D2, which are electrically connected inseries with opposite polarity (i.e. cathodes of diodes D1 and D2 areelectrically connected together). Second rectifying circuit 610 has anelectricity obtaining end 601 between diodes D1 and D2. The electricityobtaining end 601 electrically connects to the switch controller U3. Bythe opposite polarity, the two diodes D1 and D2 rectify the AC drivingsignal to output DC driving signal at the electricity obtaining end 601.

In detail, the electricity obtaining end 601 further electricallyconnects to an end of first capacitor C9, and the other end thereofelectrically connects to the ground end GND. Switch controller U3electrically connects to an end of inductor L2, and the other endthereof connects to the output end 607. Inductor L2 can perform bothenergy storage and release and maintain the current continuity whenswitch controller U3 is switching.

In this embodiment, energy storage flyback unit 630 may include aninductor L2, a third diode D5 and a second capacitor C11. A cathode ofthe third diode D5 connects to a connecting end 603 disposed between theswitch controller U3 and inductor L2. An anode of third diode D5connects to ground end GND. An end of second capacitor C11 electricallyconnects to a second connecting end 604 disposed between inductor L2 andthe output end 607. The other end of second capacitor C11 electricallyconnects to the ground end GND. an end of a load resistor electricallyconnects to a third connecting end (not shown in FIG. 21) disposedbetween the second connecting end 604 and the output end 607. The otherend of the load resistor electrically connects to ground end GND.

Further, switch controller U3 may be a MOSFET switch or an IC shipintegrated with a MOSFET switch. Of course, in some embodiments, switchcontroller U3 may be a BJT switch. Switch controller U3 has multipleconnecting ends (also called connecting port). An electricity obtainingbranch is formed between the electricity obtaining end 601 and theground end GND. The first capacitor C9 is connected in the electricityobtaining branch in series. At least one connecting end of switchcontroller U3 electrically connects to the electricity obtaining end 601through the electricity obtaining branch. A branch at which both theelectricity obtaining branch and capacitor C9 are located electricallyconnects to the electricity obtaining end 601 through the fourthconnecting end 602. The ground end GND electrically connects to agrounding line 640. All of the third diode D5, the second capacitor C11and the load resistor electrically connect to the grounding line 640.

The bias generating circuit 600 may be further provided with a samplingcircuit to sample its working status and to be a reference of outputsignal of the switch controller. In addition, in the practicalapplication, switch controller U3 may be a chip or IC integrated with atleast a control circuit and a power switch, but the present invention isnot limited thereto.

For example, the sampling circuit may include a first sampling circuit650 and a second sampling circuit 620. First sampling circuit 650electrically connects to both the electricity obtaining end 601 (forminga connecting point 605 in FIG. 25) and switch controller U3. The secondsampling circuit 620 electrically connects to both the output end 607and switch controller U3. Switch controller U3 outputs a stable workingvoltage according to sampling signal from both the first samplingcircuit 650 and second sampling circuit 620. Configuration of thesampling circuit is related to the control manner of switch controllerU3, the invention is not limited to this. FIG. 25 is circuit diagram ofthe bias generating circuit of the first embodiment of the invention.

In other embodiments, the bias generating circuit may also be used forproviding a working voltage to a temperature sensing circuit 700. FIG.26 is circuit diagram of the bias generating circuit of the secondembodiment of the invention. FIG. 27 is circuit diagram of a temperaturesensing circuit of an embodiment of the invention. As shown in FIGS. 26and 27, the temperature sensing circuit 700 electrically connects topower converter 400 for sending temperature detecting signal to powerconverter 400. The temperature sensing circuit 700 has a temperaturesensor electrically connecting to bias generating circuit 600 b to makebias generating circuit 600 b provide a working voltage to temperaturesensing circuit 600 b.

In this embodiment, in comparison with the embodiment shown in FIG. 25,the bias generating circuit 600 b of this embodiment further includes atransistor Q3, a diode D6, a resistor R12 and a capacitor C10.Transistor Q3 may be a BJT as an example (hereinafter refer as BJT Q3).The temperature detector 700 electrically connects to BJT Q3 of the biasgenerating circuit 600 b. The collector of BJT Q3 electrically connectsto output end 607. The base of BJT Q3 electrically connects to thegrounding line with the ground end GND.

The temperature sensing circuit 700 is activated by responding to theworking voltage provided by the bias generating circuit 600 b throughthe connecting ends 701 and 702 and feeds temperature data (Vtemp) backto the controller U2 of the power converter 400. When a temperatureexceeds a threshold value (indicating a situation of overheating), thecontroller U2 of the power converter 400 would reduce output power todecrease temperature and guarantee the safety during operation.

Moreover, as shown in FIG. 28, the temperature sensing circuit 700further electrically connects to a temperature compensator 800. FIG. 28is circuit diagram of a temperature compensator of an embodiment of theinvention. Temperature sensing circuit 700 electrically connects betweentemperature compensator 800 and bias generating circuit 600 b.Temperature compensator 800 electrically connects to power converter400.

Temperature compensator 800 makes a reference temperature of a free endof the temperature sensing circuit more reasonable. The temperaturecompensator 800 in this embodiment can be implemented by a comparator CP(but not limited to this). An input end of comparator CP receives avoltage, indicating a temperature information, through connecting end801 and compares the voltage indicating the temperature information witha reference voltage Vref of another input end of comparator CP, suchthat whether the temperature sensed by the temperature sensing circuit700 exceeds a threshold value can be determined and a temperaturesensing result signal Vtemp indicating whether the sensed temperatureexceeds a threshold value is generated at an output end of thecomparator CP. The output end of the temperature compensator 800electrically connects to the controller U2 of the power converter 400 tomake the temperature sensing result signal Vtemp fed back to controllerU2 of power converter 400, so that controller U2 can adjust the outputpower depending on the system environment temperature.

In detail, a circuit diagram of the temperature compensator 800 may beas shown in FIG. 28. It should be noted that, the temperaturecompensator 800 can be implemented by various manners. The invention isnot limited to the circuit shown in FIG. 28.

The above depiction has been described with reference to theaccompanying drawings, in which exemplary embodiments of the disclosureare shown. This disclosure may, however, be embodied in many differentforms and should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art.

What is claimed is:
 1. An LED (light emitting diode) lamp comprising: alamp shell; a passive heat dissipating element having a heat sinkconnected to the lamp shell, wherein the heat sink comprises fins and abase; a power source disposed in the lamp shell; a light emittingelement connected to the base of the heat sink of the passive heatdissipating element and comprising LED chips electrically connected tothe power source; a first channel defined in a chamber of the lamp shellfor dissipating heat generated from the power source while the LED lampis working; and a second channel defined in the heat sink and betweenthe fins and the base for dissipating the heat of the heat sink, whichis generated from the LED chips and transferred to the heat sink;wherein the first channel comprises a first end on the light emittingelement to allow air flowing from outside of the LED lamp into thechamber, and a second end on the upper portion of the lamp shell toallow air flowing from inside of the chamber out to the LED lamp;wherein the second channel comprises a third end on the light emittingelement to allow air flowing from outside of the LED lamp into thesecond channel, and flowing out from spaces between every adjacent twoof the fins; wherein the light emitting element further comprises anaperture communicating simultaneously with both the first channel andthe second channel by connecting with the first end of the first channeland the third end of the second channel.
 2. The LED lamp of claim 1,wherein the aperture is located in a central region of the lightemitting element, and the aperture forms an air intake of both the firstchannel and the second channel.
 3. The LED lamp of claim 2, wherein thelight emitting element comprises a first surface and a second surfacewhich is opposite to the first surface, the LED chips are mounted on thefirst surface and surrounding the aperture, and the second surface is incontact with the base of the heat sink, such that heat generated fromthe LED chips is able to be transferred to the fins through the basewhile the LED lamp is working.
 4. The LED lamp of claim 1, wherein theheat sink comprises first fins and second fins, bottoms of both thefirst fins and the second fins in an axis of the LED lamp connect to thebase, the first fins interlace with the second fins at regularintervals, and one of the second fins includes a third portion and twofourth portions, the two fourth portions are symmetrical about the thirdportion.
 5. The LED lamp of claim 1, wherein the lamp shell including alamp head, a lamp neck and a sleeve, the lamp head connects to the lampneck which connects to the sleeve.
 6. The LED lamp of claim 5, whereinthe power source having a first portion and a second portion, the firstportion of the power source is disposed in both the lamp neck and thelamp head of the lamp shell, and the second portion of the power sourceis disposed in the heat sink of the passive heat dissipating element. 7.The LED lamp of claim 1, further comprising a lamp cover with a lightoutput surface and an end surface, wherein the end surface is formedwith a vent to let air flowing from outside of the LED lamp into boththe first channel and the second channel through the vent.
 8. The LEDlamp of claim 7, where the first end is projected onto the end surfacein an axis of the LED lamp to occupy an area on the end surface, whichis defined as a first portion, another area on the end surface isdefined as a second portion, and the vent in the first portion isgreater than the vent in the second portion in area.
 9. The LED lamp ofclaim 1, wherein a ratio of power of the LED lamp to heat dissipatingarea of the heat sink is 1:20˜30.
 10. The LED lamp of claim 9, whereinthe ratio of power of the LED lamp to heat dissipating area of the heatsink is 1:22˜26.
 11. The LED lamp of claim 10, wherein the ratio ofpower of the LED lamp to heat dissipating area of the heat sink is 1:25.12. The LED lamp of claim 1, wherein a volume of the heat sink accountsfor 20%˜60% of an overall volume of the LED lamp.
 13. The LED lamp ofclaim 12, wherein the volume of the heat sink accounts for 25%˜50% of anoverall volume of the LED lamp.
 14. The LED lamp of claim 1, whereinoverall weight of the LED lamp is less than 1.7 Kg, When the LED lamp isprovided with power of 200 W, the LED chips are lit up and emit luminousflux of at least 25000 lumens.
 15. The LED lamp of claim 7, furthercomprising an inner reflecting surface disposed inside the light outputsurface of the lamp cover and an outer reflecting surface disposed inthe outer circle of the array of the LED chips, wherein the innerreflecting surface is configured to reflect part of light emitted fromthe inmost of the array of LED chips, the outer reflecting surface isconfigured to reflect part of light emitted from the outermost of thearray of LED chips.
 16. The LED lamp of claim 15, wherein total luminousflux of the light reflected by both the inner reflecting surface and theouter reflecting surface and emitted through the light output surface isat least 1500 Im.
 17. The LED lamp of claim 5, wherein the sleeve of thelamp shell is located in the heat sink, the lamp neck projects from theheat sink, height of the lamp neck is at least 80% of height of the heatsink.
 18. The LED lamp of claim 4, wherein each of the first fins isdivided into two portions in a radial direction of the LED lamp, the twoportions are divided with a gap portion, the third portion is connectedto the fourth portion through a transition portion, the transitionportion has a buffer section and a guide section, a direction of anytangent of the guide section is separate from the gap portion.
 19. TheLED lamp of claim 15, wherein in the projected area of the LED lamp,there is a light concentrating area within the projected area, andluminous flux of the light projected by the LED lamp onto the lightconcentrated area accounts for 35%˜50% of the total luminous flux. 20.The LED lamp of claim 1, wherein at least partially of fin has aprotrusion projecting from a surface of the fin, the protrusions extendalong an axis of the LED lamp and are in contact with the base.